Typewriting machine



May 4, 1937. R. v,. REPPERT TYPEWRITING MACHINE Filed Dec. 18, 1933 2 Sheets-Sheet 1 It .l Q

/m/entor R. v. REPPERT TYPEWRITING MACHINE Filed Dec.

May 4, 1937.

18, y1933 2 Sheets-Sheet 2 Patented May 4, 1937 I PATENT OFFICE 2,079,425 TYPEWRITING MACHINE Richard v. Reppert,` Teaneck, N. J., assigner to International Business Machines Corporation, New York, N. Y., a, corporation of New York Application December 18, 1933, Serial No. 702,856

21 Claims. A(Cl. 197-17) My invention relates to an improvement in typewriting machines and more particularly to a power mechanism. for the type bar action,

whereby the typewriter keys have merely a selecting function, to operatively connect the respective type bar action with the universal, power driven actuator.

In distinction to the manually operable machine wherein the keys may be oper-ated at low or high speed, the power operated machine is adjusted to operate at a high speed,irrespective of the operation of the keys and therefore the mechanism thereof is subjected to far greater wear than that of the manually operable machine. l5 An important provision of this invention is,

that upon engaging or coupling a type bar mechanism with the rapidly rotating actuator or rotor, only a small mass is moved and a small resistance overcome, to thereby avoid any shock incidental to such engagement and the wear and noise resulting therefrom and further to provide for a gradual increase of load or resistance, as the rotor continues its movement.

Another important provision is the distribution of the transmission of movement from the power rotor, to the type bar mechanism, over an appreciable part of the rotation of the rotor, to thereby reduce the contact pressure between the engaged members and correspondingly reduce the wear of these parts.

A further feature is, the provision of a toothed rotor, which is continually rotated and of a toothed disc for each type bar action, the disc being engaged with the rotor, upon operation of the respective key, but the engagement of the disc being constrained, so that a disc tooth will not enter into the path described by the rotor teeth,y until the rotor is in a certain, predetermined position, in which the disc toothV Will properly engage a tooth space of the rotor. Thereby any clashing or impingement of the teeth and the resulting noise and wear are eliminated.

This invention valso provides for positive actuation of the type bar, in distinction to frictionally driven mechanism, to assure uniform typing and to obviate wear resulting from the necessity of strong contact pressure between frictionally coupled devices.

Another feature lies in the simple and durable construction of this invention, which readily makes it responsive to the high' speed required.

The key releases a tootheddisc, mounted on a swingable lever, which is under spring vtension and engages the disc with the power driven,

toothed rotor. Upon engagement with the rotor, the disc is unlocked and as the disc represents a very light mass and is entirely free to rotate, the engaging contact is free from shock. The rotation of the disc rst moves the disc and its lever, 5 to and slightly beyond initial or normal position, where the lever is relocked by the key mechanism. During this part of the disc rotation, a disc tooth has commenced to actuate a cam, mounted on a lever, directly connected to the type bar. 'Ihe 10 further rotation of the disc continues to actuate the cam lever and the type bar and as the cam has an accelerating curve, the type bar is moved with accelerated movement. In View of the speed with which the mechanism operates, it is neces- 15 sary to move the type bar only approximately one-half of its total motion by the action of the cam and it will complete its motion by momentum force.

Another provision is, the positive locking of the 20 disc against rotation in both directions at all times except when in engagement with the rotor. The importance for such locking of the disc against accidental rotation, will be understood when the speed is considered with which such 25 devicesmust operate, Ato meet the requirements of practicability and which requires a rate of thirten to fifteen operations per second. Such speed produces momentum forces, which will readily cause over-rotation of even very light 30 bodies and hence the requirement of constrained locking of the disc.

A further object is, to provide a cam action for the actuation of the typing devices by extending a cam lever into the tooth space of the disc, 35 so that the cam lever is actuated by a disc tooth, upon rotation of the disc. vBy shaping the cam outline to conform to an accelerating curve, a gradual acceleration of the type bar action is obtained. This produces the important advantage, 40 that the initial rotation of the disc can be pr tically Without load and thereby, shocks and the resulting Wear and noise are avoided.

Another advantage is, that the disc has a short engaging movement, so that the iirst part of its 45 rotation can be utilized for resetting the disc and its lever and to utilize the second part of its rotation for actuating the typing devices. The advantage of this provision is, that .the initial rotation of the disc meets with very little resist- 50 ance and further, that the largest load is overcome, when the engagement of the teeth of the disc and rotor, represent a condition of proper gearing with partly rolling. and sliding contact.

Another feature is, to 4provide surface contact 55 Y type bar action, in which writes familiar words or chine is xedly set to provide the proper impact between a disc tooth and the rotor tooth space,

when these members are engaged for rotation,

book-keeping machines, such as are shown in the Patent No. 1,928,656, issued to me. This feature is also applicable in connection with remote control devices such as the teletype machines.

One of the features of this invention is, the provision of a type bar impact force control, whereby an operator can regulate the impact or typing force,- to suit the work at hand.

As is understood, power operated typewriters are adjusted to operate at high speed, in order to respond to the fast operation when an operator phrases. If the maforce, for writing a few carbon copies,-at this speed, the impact force will ha\ e to be increased,

by increasing the machine speed, if a large mimber of carbon copies are to be typed. Such. increase of speed however, is very undesirable as it causes excessive wear. Furthermore, the type bar and its associated parts, even when made as light as permissible, represent a mass, which, whenl moved at the required speed, produces a surplus kinetic energy or impact force, which must be absorbed in order to prevent the cutting of the paper. In this application, the power mechanism is shown as applied to the well known Underwood the type bars actuate a universal frame, whenr nearing typing position, for the purpose of actuating the escapement mechanism. As this frame is spring-held in normal position, it offers a convenient means for regulating the impact force, by increasing or decreasing the tension of the spring. By these means, any surplus impact force produced at the proper writing speed, can be absorbed harmlessly and toobtain suiilcient impact force for writing a large number of copies, the spring tension is decreased. The usual speed control for the machine may be retained and in connection with the impact force control, provides the means for operating the machine more slowly and yet obtaining suiiicient typing force; thereby further reducing the wear of the machine.

Another feature e load release device for each type bar action, to thereby safeguard the parts against distortion or breakage, in c ase the movement of a type bar is interfered with.

Another advantage is the provision of lubrication for the power mechanism, whereby lubrication is automatically carried to the parts requiring lubrication.

Other features and advantages will hereinafter appear. y

In the accompanying drawings,

Figure 1 is a partial longitudinal section through a typewriting machine and shows this invention applied thereto.

Figure 2 is a detail view of this invention showng the position assumed by the actuating disc immediately after its release by the key mechanism is, the provision of an overand held against engagement with the actuating rotor by the peripheral land of a rotor tooth.

.Figure 3 is a detail view of the parts of this invention, showing the position of the disc during its engaging movement with the rotor.

Figure 4 is a detail view of the parts of this invention, showing the position assumed by the disc upon com pleted engagement with the rotor.

Figure 5 is a detail view of the parts of this invention showing the position of the disc assumed when actuated approximately one half of a cycle or pitch.

Figure 6 is a detail view of the parts of this invention, showing the position assumed by the disc when its rotary motion is prevented by an interference with the motion of the type bar and the overload device functions to permit the by-pass of the engaged tooth.

Figure '1 is a partial plan view of this invention.

Referring to Figures l and '7, a general operator or rotor is mounted onL a shaft 2 running in suitable bearings in the typewriter side plates 6 and 'i and this shaft is driven by a worm wheel 3, which in turn is actuated by the worm 4 mounted on the armature shaft of the motor 5, suitably mounted adjacent to the typewriter frame. 'Ihis rotor has teeth extending its entire length and resembling sawteeth in outline. with rounded edges and rounded tooth spaces. A

toothed disc 8 is provided for each type bar action and is journaled on a lever 9. This lever, which has the shape of a bell crank, is built up of two plates of thin material which are joined closely together for a portion of the horizontal arms, to form one piece and the other portion, including the vertical arms, is spread apart to receive the disc 8. The levers 9 are fulcrumed on the transverse shaft il and are heid in proper alignment by the transverse plate I5 which has extensions or tongues i5', extending between the two side plates of the levers and the horizontal arms of ythe levers are aligned by the transverse angle plate I6, by passing through slots therein.

'Ihe disc 8 is constrainedly locked against rotation in the actuating sense, as indicated by the arrow, by the transverse ,lock plate i1 and also constrainedly locked against rotation in the reverse direction by a notch in a detent i2, pivoted between the side plates of lever 9, engaging a disc tooth.

A spring I3, connected to the detent I2, has the function to lock the disc against back-rotation, as stated, and also tends to oscillate the lever 9 and move the disc into engagement with the rotor, upon release of the lever by the respective key mechanism, as will be set forth directly.

The keys I9 are pivoted on the transverse shaft i9 and are held in alignment by slots in the transverse angle plate 2|. Springs 20, connected to the downward extensions I9' of the key levers, hold the keys in'normal position, with the exten` sions bearing against the bottom of the slots in the angle plate 2|.

A detent 22 is mounted on each key extension and the downwardly extending arm thereof, en-

gages the lock surface 29 of the disc lever 9 and a spring 24 holds the detent against a stop 23, to maintain it in proper position. Upon depression of a key, the detent 22 will be moved oi of the lever lock surface 29 as shown in Fig. 2 and lever 9 will, under the impulse of its spring I3, oscillate to move the horizontal arm upward and to move the disc 8 toward the rotor and into engagement therewith, if Vat this instant the rotor is in engaging POSition.

In view of the high speed with which these mechanisms must function, it is necessary to rotate the rotor at a high speed, which impliesa. high peripheral velocity. It will be readily understood that a haphazard engagement of the toothed ydiscwith the rotor would cause clashing of the teeth and result in excessive wear and noise. For this reason, provision has been made to control the engagement of the disc, so that engagement thereof with the rotor will only take place at certain, predetermined positions of the rotor, in which a disc tooth will gradually enter a tooth space and properly bottom therein, with its curved. outline fitting the curved outline of the tooth space, as is shown in Fig. 4. As the disc has appreciable width,this provides a surface contact between the two members at the instant of contact and as both members can be made of hardened steel, good wearing qualities are assured. To attain such proper engagement of the disc, as stated, provision is made to' lock the disc against engagement when the rotor is not in proper postion at the instant when the disc is released by its key. Referring to Fig. 1,v it will be seen that if the disc were released at the instant when the rotor is in the position as shown, the disc would have a very short movement toward the rotor until its tooth S2 would bear against the peripheral surface of the tooth R3 of the rotor and thereby be locked against further movement until the tooth space between the rotor teeth R3 and R4 has moved a short distance and permits the gradual engagement of the disc tooth S2. The disc is prevented from back-rotation, `at this phase, by the detent I2.

Referring vto Fig. 2, the rotor is shown in another position in which engagement of the disc` is prevented from rotary movement in the actu- `the spring I3.

Fig. 3 shows the relation `of the parts after a proper engaging movement of the disc has taken place and the disc tooth S2 has enteredthe tooth space lbetween the teeth R4 and R5 of the rotor and the tooth S4 has moved on the arc n` and clears the lock plate I1 and stands free to rotate. Under the impulse of the spring I3 and with the disc tooth SI bearing against the peripheral surface of tooth R3 of the rotor, the disc will have aslight rotary motion to bottom the tooth S2 into the rotor tooth space. It will be seen that the notch of the detent I2 does not oppose such rotation of the disc, as it presents an angular surface to such motion. The position then assumed is shown in Fig. 4, which shows the disc in complete engaged position.

In this position, the disc tooth S3 is in contact with a cam 33 on the lever 32, which actuates the type bar 36, With a slot and pin connection, in the well known manner, see Fig. l.

The levers 32 are mounted in slots in the transverse bracket 35 and are journaled on the shaft 36, extending through the bracket. The cams extend between the tooth spaces of the discs and into the path described by the teeth thereof-and are held in this position by the springs 3 I.

To provide good wearing qualities, the individual cam is made of a thick piece of steel and preferably of a. separate piece, riveted to the lever, as shown in Fig. 1. Ihe cam is shaped to provide gradually accelerated movement of the lever 32 and the type bar associated therewith, so that the initial rotation of the' disc meets with very little resistance and therefore no shock results from such movement, which would be very objectionable as it would cause excessive wear and noise.

Fig. 4 shows the cam in its normal position, as indicated by the arc y and Fig. 5 shows the relative position of the parts, when the disc has been rotated approximately one-half cycle and in this position, the cam has been moved only a short distance and the rotor tooth R5, has partly rolling and partly sliding contact with the disc tooth S2. As the load or resistance is greatest, near this position, it is highly desirable that such conditions be provided, in order to obtain good weare ing qualities of the parts.

Upon further rotation of the disc, the cam lever will be actuated with accelerated movement, until the cam leaves the path described by the disc tooth S3, denoted by the arc :I: and will, by reason of the inertia of motion, continue its movement until the type bar strikes the platen to type.

The normal position of the disc and its lever is shown in Fig. 1 and the center of the disc is denoted by the letter a. 'I'he disc teeth SI and S2 are a short distance from the rotor periphery and the lock surface 29 of the lever bears against the lock surface 25 of the detent 22. Upon release of the disc lever, by the operation of the key or by the operation of the detent 22, by the electrical devices, the lever is free to move, under the impulse of its spring I3 and if the rotor happens to be in engaging position the lever and disc will directly assume engaged position, as is shown in Fig. 4, in which the vdisc center is denoted by the letter b.

In this position the motion relation of the rotor and the disc, represent a toggle linkage, which, by the rotation of the rotor will be straightened out and impart translatory movement to the disc in reverse direction to its engaging movement and thereby reset the disc and its lever.

The various positions assumed by the disc center during a cycle are indicated by the letters a, b and c and the positions assumed by the lock surface 29 of the disc lever are correspondingly denoted by the same letters. It Will be seen that the disc is moved from position b, its engaging position, to position c, slightly beyond its normal position (see Fig. 5) and the lock surface 29 of the disc lever is moved from position b to position c, slightly below the lock surface 25 of the detent 22; thereby leaving the detent free to move into locking position, when the key is released.

Fig. 5 shows the relative position of the parts in half-cycle position, when the key is still in depressed position. If now the key is released quickly, the detent 22 will move into the position shown in Fig. 1 and prevent the lever from moving beyond normal position, under the impulse of its spring and will hold it there, ready for the next key operation. To prevent the lever from moving beyond normal position, in case the key isnot released q uickly, an auxiliary detent 26 is mounted on the key extension and the spring 2li notmally holds it against a stop pin 21. with its stop surface 28 extending slightly below the stop surface 25 of the detent 22. See Fig. l. lln this position, the rear edge of the detent 26 is adjacent to the disc lever, so that when, upon operation of a' key, the lever moves upward, the detent will bear against the front edge of the lever, until the lever is reset. This happens at approximately the one-half cycle position, as shown in Fig. 5 and the detent will then, under the impulse of the spring 24, move rearward, over the lock surface 29 of the lever and intercept the lever on its upward movement and hold it, until the key Vis released and the stop pin 21 moves the detent off of the lever lock surface. In this position however, the detent 22 has reassumed its normal position, in which it will intercept and hold the disc lever in its normal position.

' From the foregoing it will be seen that during the initial rotation of the disc, very little resistance must be overcome as the movement of the disc lever is short and the mass is small and that the real work, that of actuating the typing devices, is done under the most favorable conditions and by gradual acceleration. 'Ihe disc represents a light mass and is free to rotate; furthermore, its movement is positive in every respect and it is held against over-rotation at all times. The rotor moves through an appreciable angle during one cycle movement and the work is distributed over this angular movement and in the proper manner, that is, commencing with a small load and gradually increasing the same.

In such mechanisms as this, it is advisable to provide safeguards against distortionyor breakage of parts, in case the movement of the type bar is interfered with. 'Ihe result of such interference would be that the lever 32 would be prevented from completing its movement and this in turn would prevent the disc from completing its cycle and as a disc tooth is in engagement with the rotor during a cycle, such interference would bring appreciable force into play, in view of the kinetic energy of the rotor and the motor armature, with the effect that parts may be distorted or broken.

A strong spring 45 extends across the machine andunderlies the disc levers 9. See Figures l and 6. Normally, this spring just bears against the lever and holds it against downward movement during the normal rotation of the disc and against the reacting force resulting from the camming action of the disc tooth and cam 33.

If however, the lever 30 is held against movement by an interference, the point of contact between the disc tooth S3 and the cam 33, becomes the center of rotation for the translatory movement of the disc and the rotor will force the'disc tooth S2 out of engagement and thereby force the disc lever back and the horizontal arm thereof downward, against the tension-of the spring 45, thereby by-passing the disc tooth S2, as is shown in` Fig. 6. The continued rotation of therotor will keep the disc in this disengaged position.

To provide lubrication for the mechanism, an oil wick 65, is carried in a trough 66 mounted on the cross member 61 and its upperv edge bears on the rotor and keeps it oiled. From the rotor, the oil is vdistributed to the disc, whenever the disc engages and from the disc it is carried to the cam 33, the detent I2 and the lock plate l1.

Such mechanism as this invention discloses,

l may be very useful in connection with remote control operation and also in connection with the automatic total printing devices of bookkeeping machines, wherein typing mechanisms are automatically selected for electrical operation.

acreage To meet such requirements, suitable means for electrical operation, in addition to the manually operated keys, have been provided. It is essential, that for electrical operation, the mass to be moved be h'eld to a minimum, in order to be enabled to use small and quick acting magnets.

A series of small magnets M are mounted in the frame 38, extending across the machine and are arranged in two rows, to permit the use of larger magnets and if desired, an additional frame with magnets can be mounted adjacent to the rst one. For each magnet, a small armature 39 is pivoted on the extension 40 on the frame and a wire connector 4I extends from the armature to the arm 44 of a small bell crank 43. These bell cranks are mounted in slots in the transverse bracket 42 and are fulcrumed on the shaft 4l, extending through the bracket. 'I'he arms 43 of the bell cranks overlie the arms 31 of the lock detents 22, which are provided for this purpose, as otherwise these detents could be eliminated and their function could be performed by an integral part of the key extensions. It will be seen, that the manual operation of a key does not influence the electrical devices and vice versa, the electrical operation does not affect the key, which remains in its normal position. The mass represented by the detent is very small and therefore small and quick acting magnets will suiiice for the operation of this power mechanism.

It is, of course, understood that an operation of detent 22 will induce the power mechanism to function, as has been described and it is also understood, that the number of magnets provided,

depends upon whether or not all of the type bar actions shall be operated electrically or only certain ones thereof, as 4for instance the vnumeral type bar s of a bookkeeping machine.

In the manually operated machine, the operator controls the speed of operation and the impact force. The speed of operation, or the speed with which the keys are-operated in succession, may be very high and a speed rate of thirteen operations per second, is common. Such speed may not be sustained, butwll be used for writing familiar words and phrases,

The impact force is also affected by the distancea key is operated and with fast key operation, an operator will not always bottom the key and the type bar will not be moved the complete distance by hand, but will move by momentum force, to type. During its momentum movement it loses speed and therefore impact force, so that a high speed of operation and a normal impact force are obtained. For a larger number of copies, the key operation must be both complete and quick.

In power operated machines the conditions are different, in that, the power mechanism will al- Ways actuate the typing devices to the same extent and that it must be set to respond to the required high speed. If the impact force is regulated to sumce for ordinary purposes, it will be insumcient for a large number of copies and the usual method is, to further increase the machine speed, to thereby increase the impact force. Such increase of speed, beyond the operating requirements, is very undesirable, as it causes excessive wear and therefore I prefer to provide sufficient impact force for multiple copy writing at ordinary speed and to provide means for dissipating so much thereof as is not needed for the particular work at hand.

The type bar action shown herein is the well known Underwood type bar action. wherein the type bars actuate a universal frame 50 for the purpose of actuating the escapement and the frame is held in normal position by a spring 55 which, in the Underwood machine, ,is iixedly mounted on the lframe of the machine.

In this invention, the spring is fastened to a lever 54, mounted on a shaft 53, extending from I y'I'he turning of the knob in one direction will move the lever 54 to increase thev tension of the spring 55 and thereby decrease the impact force correspondingly and turning of the knob in the opposite direction will increase the impact force correspondingly.

It will be understood that for different type bar actions, the impact force control will be applied differently, without deviating from the principle- Variations may be .resorted to within the scope of ymy invention and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a power mechanism for typewriters, the combination, with a device to be operated, of a universal power actuator, a rockable support; a coupling member rotatably mounted on the support and having a series of cam elements positively engageable `with the actuator for rotation by the latter when-the support is rocked, a sublever connected to the device to be actuated and having an arm adapted to be engaged by the cam elements whereby the sub-lever is rocked when the coupling member rotates, means for rocking the support whereby to engage the cam elements on the coupling member with the actuator, and means for controlling theA rocking means.

2. In a power drive mechanism for typewriting machines, the combination with a device to be operated, of a universal power actuator, a movable support, a multi-lobed cam rotatably mounted on the support and adapted to engage said actuator when the support is moved, whereby said actuator rotates said cam by energizing 'one oi its lobes, a sub-lever connected'to the device to be operated and having an arm projecting into one of the spaces between the lobes of the cam whereby a partial rotation of the cam operates the `sub-lever, and means to control the movement of the support to engage the cam with the actuator.

3. In a power mechanism for typewriters and the like, the combination with a typing device. of

a universal ,power rotor provided with teeth, a lever under spring tension; a toothed disc rotatably mounted on said lever and adapted, when the lever is rocked, to engage the teeth of the rotor for rotation by the latter; a cam lever operatively connected to the disc to be actuated by the teeth thereof, means connected to the cam lever to actuate the typing device, key mechanism having means to normally lock the lever with the disc out of engagement with the rotor and to release said lever upon depression of the key to thereby permit the disc to engage the rotor for an actuation thereby and having means to relock the lever after one actuation of the disc irrespective of the position of the key.

4. In a power mechanism for typewriters andthe like, the combination with a device to be actuated, of a power driven toothed actuator having locking surfaces between the teeth, a rotatable disc having teeth adapted to engage the teeth and lock surfaces of the actuator, means to lock the disc against rotation while the teeth of the disc are-engaging said lock surfaces in the actuator, said locking means being released when the teeth of the disc positively engage the teeth of the rotor, means to c ontrol the engagement of the toothed disc with the actuator, andA means connecting the disc to the device to be operated whereby rotation of said disc operates said device.

5. In a power drive mechanism for typewriters and the like, the combination with a device to be operated, of a power driven actuator provided with teeth and locking surfaces between the teeth, a movable support; a coupling element pivotally mounted on said support and having teeth adapted, when the support is moved, to engage said locking surfaces and teeth of the actuator, and, when engaged by the teeth of the actuator, to be pivotally and positively moved by the actuator; means to move the support to bring the coupling element into engagement with the'actuator; means to prevent rotation of the element when the teeth in theelement are engaging the lock surfaces in the actuator, said means being rendered ineffective when the teeth of the actuator positively engage the teeth of the element; means to control the movement of the support, and means connecting said element and the device to be operated whereby the pivotal movement imparted to said 4element by the actuator operates the device to be operated.

6. In a power drive mechanism for typewriters and the like the combination of a moving power driven actuator having an abutment and a locking surface of predetermined extent spaced from the abutment; a rockable coupling element movable into engagement with the actuator for pivotal positive driving engagement with the abutment on the actuator, said element, when conditions are unfavorable for positive driving engagement with said abutment, engaging the locking surface on the actuator for a predetermined period; and means operative to positively prevent pivotal movement of said element while it is moving into engagement with the locking surface and while said element is engaging said locking surface, said means being disengaged automatically when the abutment positively engages said element.

'7. In a key controlled power mechanism, thel combination, with a device to be operated, of a power driven toothed rotor with peripheral lockV surfaces on the teeth, a lever under spring tension; a toothed disc rotatably mo".' nted on the lever and adapted, when the lever is released, to be operatively connected with the rotor by the projection of a disc tooth into a rotor tooth space; if

a lock plate engaging one of the disc teeth to lock the disc against rotation when disengaged from the rotor and to maintain the disc locked until one of its teeth has entered a tooth space of the rotor and to relock it upon disengagement of its teeth from the rotor, a lock detent adapted to lock the disc against rotation in reverse direction to prevent engagement of the disc with the rotor teeth when the lever is released and oner of the disc teeth bears against the lock surface of a rotor tooth, key mechanism having means adapted to release the lever for engaging movement of the disc with the rotor and to relock the lever after one actuation ofthe disc by the rotor, and means operated by the disc for actuating the device to be operated.

8. In a power drive mechanism for typewriter the combination with a device to'be operated, of a power driven universal actuator, a couplingV member adapted to be operatively engaged with the actuator for operation by the latter, means for moving thev coupling device into engagement with the actuator, means operated 1 by the coupling member when engaged with the actuator for actuating the device to be operated, and an overload device adapted to permit the coupling member to complete its operation when the device to be actuated is obstructed from operation.

9. In a power mechanism for typewritersand the like, the combination with a type bar, of a universal power driven actuator, a coupling member adapted to be connected with the actuator for actuation thereby, means tending to operatively connect the coupling member with the actuator, key mechanism having means to release the coupling member for operation by the first named means whereby to connect the coupling member with the actuator, means connected to the coupling member to actuate the type bar, and means to hold the coupling member in connected relation with the actuator during actuation by the latter and adapted to yield to permit disengagement of the coupling member from the actuator when free movement of the type bar is obstructed.

10. In a key controlled power mechanism, the combination, with a device to be operated, of a power driven toothed rotor, a lever under spring tension; a toothed disc rotatably mounted on the leverand adapted, when the lever is released, to be engaged with the rotor for rotation thereby; a lock member to lock the disc against forward rotation when disengaged from the rotor, a lock member to lock the disc against backward rotation when disengaged from the rotor, key mechanism having means to release the lever to permit the disc to engage with the rotor and to reiockthe lever after one actuation of said disc by the rotor, a cam lever actuated by the rotation of the disc and means connected to the cam lever to actuate the device to be operated.

11. In a power mechanism for typewriters and the like, the combination of a power 'driven ,toothed rotor, a lever under spring tension; a'

toothed discv rotatably mounted on the 1ever and adapted when the lever is released to beengaged with the rotor for rotation by the latter; a nxed lock member adapted to lock the disc against forward rotation when disengaged from the rotor, a second lock member adapted to yieldingly lock the disc against backward rotaticn when disengaged from the rotor, key mechanism having means to release the lever to permit the disc to engage the rotor and to relock theI lever after one actuation of said disc bythe rotor, a cam lever adapted to be actuated by a tooth of said disc upon rotation of the disc by the rotor, and a type bar operatively connected to the cam ever.

12. In a power mechanism for typewriters and the like, the combination with -a type bar, of a power driven toothed rotor, a rockable lever under spring tension; a toothed disc rotatably mounted on said lever and adapted, when the lever is rocked, to be engaged with the rotor for rotation by the latter; means to constraiuediy hold the disc against rotation in both directions when it is disengaged from the rotor; a cam lever connected to the type bar and extending into a tooth space of the disc, said lever being adapted to bel actuated by a disc tooth upon rotation ofthe disc; and key mechanism havingmeans to release the rst named lever to permit the disc to engage the rotor and to relock the rst named lever after one actuating cycle of the toothed disc.

13. In a key controlled power, mechanism, in combination,` with a device to be operated, of a power driven toothed rotor, the teeth on the rotor having approximately Saw tooth outline with rounded ends, rounded interdental spaces, and peripheral lands; a lever under spring tension; a toothed disc having elongated teeth with rounded ends and having wide tooth spaces; said disc being rotatably mounted on the lever; means to lock the disk against rotation in both directions when disengaged from the rotor, key mechanism having means to release the disc lever to permit a disc tooth to engage with a rotor tooth space and to relock the lever after rotation of the. disc one tooth space, a cam lever extending into a tooth space of the disc to be actuated by a disc tooth upon rotation of the disc one tooth space, and means connected to the cam lever to actuate the device to be operated.

14. A power drive mechanism -for typewriting machines comprising a device to be actuated, a constantly operating power operator; a device for coupling the device to the power operator including a rockable support, means for rocking said support, releasable means for holding the supportA in an inactive position, an velement rotatably mounted on said support and adapted to actuate the first named device by positive rotative engagement with the power operator when the support is rocked, the initial movement of said element and operator cooperating to restore ythe support to the control of the holding means and, by continued movement of the power operator, to actuate the first named device; yielding means for holding the rotatable element against rotation until said element is positively engaged by said power operator; and means for releasing' the holding means.

15. A power drive mechanism for typewriting machines comprising a device to be actuated, a constantly operating power operator; a device i'or coupling the device to the power operator including a rockable support, means for rocking said support, releasable means for holding the support in an inactive position, and an element rotatably mounted on said support and adapted to actuate the ilrst named device by rotative engagement with the power operator when the support is rocked, the initial movement of said element and operator cooperating to restore the support to theV control of the holding means and, byl continued movement ofthe power operator, to actuate the rst named device; means for releasing the holding means; and yieldable meansior normally limiting the restoring movement of the Y support, said yieldable means, when vthe device to be actuated is obstructed from freemovement, yielding under the power of the power operator to permit continued rotation of the rotatable element without damage to any of the parts.

16. In a power drive mechanism i'or typewriting machinesa printing instrumentality, a constantly, operating power operator, adevice for coupling the printing instrumentality to the power operator including a rockable support, means for rocking said support. reieasable means for holding the support in an inactive position, and an element rotatably mounted on said support and adapted to actuate the iirst named device by rotative engagement with the power operator when the support is rocked, the initial movement of said element and operator cooperating to restore the support to the control of the holding means and, by continued movement of the power operator, to actuate the first named device; means for releasing the holding means; and a resilient stop for normally limiting the restoring movement of the support, said stop, when the device to-be actuated is obstructed from free movement, yielding under the power of the power operator to permit continued rotation of the rotatable element without damage to any of the parts.

17. In combination with a device to be operated, a power actuator, a rockable support, a multi-lobe cam rotatably mounted in said support, means to rock said support to engage one of the lobes of the cam with the actuator, means to limit rotation of the cam to the angular distance between two of its lobes; a sub-lever connected to the device to be operated, a part of said sub-lever projecting into the space between the lobes of the cam whereby partial rotation of the cam operates the sub-lever; and means to control the rocking of said support to engage the cam with the actuator.

18. In power drive mechanism for typewriting machines, in combination with a device to be operated, a toothed power actuator, a rockable support; a star wheel mounted on said support and adapted, when the support is rocked, to positively engage the actuator for operation by the latter means connected to said device whereby rotation of the star wheel actuates said device, means to prevent rotation of the star wheel until the teeth on the latterand the teeth of the actuator are in a predetermined relation, and means to rock said support.

19. In a power drive mechanism for typewriting machines, the combination with a device to be operated, a power actuator, a member for operating said device, means to couple the member to the actuator whereby the latter positively operates said member and said device, and means' associated with the coupling means to enable it to complete its operation in the event free operation of said device is obstructed whereby said member exerts a binding iniiuence on the coupling means.

20. In a power drive mechanism for typewriting machines, the combination with a device to be operated, a toothed power actuator, a toothed coupling element engageable with said actuator for positive operation by the latter, means connecting said element to the device to be operated, a support for the coupling element'movable to engage the latter with the actuator, means to move the support, and means to hold the support in non-engaging position including a releasable latch and a yielding stop, said moving means engaging the coupling element when the latch is released to eiect an operation of said device, said stop being operative, when free mo'vement of said device is prevented, to permit the coupling element to operate idly.

21. In power drive mechanism for typewriting machines, the combination with a device to be operated, a power actuator, a coupling device engageable with the actuator for operatively coupling said device to said actuator; a yielding mounting for said coupling device operative,when -5 the device to be operated is obstructed, to permit complete actuation of the coupling device, and means to control engagement of the coupling device with the actuator.

RICHARD v. REPPERT. 

